FXUS65 KVEF 141702 AFDVEF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 1002 AM PDT FRI AUG 14 2015 .SYNOPSIS...SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY ACROSS PORTIONS OF THE AREA AS MOIST...UNSTABLE CONDITIONS REMAIN IN PLACE. LESS STORM COVERAGE AND WARMER TEMPERATURES ARE EXPECTED SATURDAY. HIGH PRESSURE WILL BECOME THE DOMINANT FEATURE SUNDAY AND MONDAY WITH VERY HOT CONDITIONS EXPECTED. A PACIFIC STORM SYSTEM IS THEN FORECAST TO BRING RELIEF FROM THE HEAT WITH TEMPERATURES CLOSER TO TYPICAL SEASONAL LEVELS AFTER MONDAY. && .UPDATE...OVERALL, THE FORECAST THIS MORNING LOOKS GOOD. ONLY MADE A FEW MINOR EDITS TO POP, WEATHER, AND SKY ACROSS TERRAIN AREAS OF FAR SOUTHERN CLARK COUNTY AND LINCOLN COUNTY, BASED ON THE LAST SEVERAL RUNS OF THE HRRR. COVERAGE OF CONVECTION IS STILL EXPECTED TO BE LESS THAN YESTERDAY. IF STORMS DEVELOP ACROSS FAR SOUTHERN CLARK COUNTY, THE STEERING FLOW IS FAVORABLE TO MOVE SOME OF THAT TOWARD THE LAS VEGAS VALLEY. ADDITIONALLY, THE KVEF 12Z SOUNDING INDICATED A FAVORABLE ATMOSPHERE FOR CONVECTION, HIGH MOISTURE CONTENT AND NO CAPPING AS WE HEAT UP THROUGH THE DAY. THERE IS A WEAK MID-LEVEL WAVE ACROSS SOUTHWEST ARIZONA THAT MAY HELP INITIATE OR ORGANIZE CONVECTION THIS AFTERNOON AS IT MOVES NORTHWARD, BUT IT IS RATHER WEAK. THUNDERSTORMS THAT DEVELOP SHOULD HAVE HIGH PRECIP EFFICIENCY, WITH A WARM CLOUD DEPTH OF 14KFT, K INDEX IN THE 30S, PW OF OVER AN INCH, AND SUB-CLOUD LAYER RH OF 40-50 PERCENT. WILL CONTINUE TO MONITOR TRENDS THROUGH THE MORNING AND EARLY AFTERNOON. && .PREVIOUS DISCUSSION... 306 AM PDT FRI AUG 14 2015 .SHORT TERM...TODAY THROUGH SUNDAY. THUNDERSTORM ACTIVITY HAS FINALLY ENDED FOR THE NIGHT ACROSS THE CWA WITH ONLY DEBRIS CLOUDINESS LEFT OVER. LIGHTNING AND ENHANCED CLOUD COVER WAS NOTED ON SATELLITE OVER YUMA COUNTY AND EXTENSIVE CLOUD COVER OVER THE PHOENIX AREA IS MOVING SLOWLY NORTHWEST BUT IT IS QUESTIONABLE WHETHER IT WILL MAKE IT AS FAR NORTHWEST AS THE CWA. CLOUDS OVER VEGAS HAS KEPT THE TEMPERATURE VIRTUALLY UNCHANGED SINCE I ARRIVED FOR WORK 8 HOURS AGO (83 AT 6 PM AND 82 CURRENTLY AT 2 AM). AN INTERESTING SIDE NOTE REGARDING YESTERDAY TEMPERATURES IN LAS VEGAS...THE LOW OF 77 DEGREES ACTUALLY OCCURRED ROUGHLY 3 1/2 HOURS AFTER THE 1:12 PM HIGH OF 103. THIS LARGE DROP IN TEMPS WAS ASSOCIATED WITH THUNDERSTORM ACTIVITY OVER THE CENTRAL AND EASTERN VALLEY. THE LARGE SCALE WEATHER PATTERN TODAY HAS LOW PRESSURE MOVING INTO THE PACIFIC NORTHWEST AND HIGH PRESSURE CENTERED OVER WESTERN NEW MEXICO. THIS PATTERN MAINTAINS THE MONSOONAL FLOW INTO THE AREA AND THIS IS SUPPORTED BY A MOIST...UNSTABLE FORECAST FOR THIS AFTERNOON ACROSS MOHAVE, EASTERN SAN BERNARDINO, CLARK AND LINCOLN COUNTIES. THE LATEST HRRR SUPPORTS SHOWER/STORM ACTIVITY IN THESE AREAS BY THE AFTERNOON HOURS. THE NAM BUFR FORECAST SOUNDING SHOWS CAPPING THIS MORNING OVERCOME BY STRONG DAYTIME HEATING COUPLED WITH AN INCH AND A THIRD PWAT VALUES AND SUFFICIENT INSTABILITY FOR AT LEAST ISOLATED STORMS LATER TODAY IN THE AFOREMENTIONED AREAS. WEAK EMBEDDED VORT MAXES ARE FORECAST TO MOVE ACROSS THE AREA TODAY AND TONIGHT BUT CURRENT THINKING IS STORM COVERAGE WILL QUICKLY DECREASE DURING THE OVERNIGHT HOURS. ADDITIONAL STORMS ARE POSSIBLE SATURDAY AFTERNOON WITH HIGH PRESSURE REMAINING EAST OF THE AREA. BY SUNDAY, THE HIGH TRANSITIONS TO SOUTHWEST ARIZONA AND SOUTHERN CALIFORNIA...END ANY CHANCE FOR STORMS. THE FORECAST CONCERN SHIFTS FROM POSSIBLE FLASH FLOOD PRODUCING STORMS TODAY AND SATURDAY TO EXCESSIVE HEAT SUNDAY. AN EXCESSIVE HEAT "WATCH" CURRENTLY OUT FOR SUNDAY WILL BE UPGRADED TO AN EXCESSIVE HEAT "WARNING". .LONG TERM...MONDAY THROUGH THURSDAY. MONDAY SHOULD BRING LITTLE TO NO RELIEF FROM THE WEEKEND HOT SPELL WITH THE MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT THAT THE STRONG CLOSED HIGH WILL REMAIN PARKED OVER THE EXTREME SOUTHERN COLORADO RIVER VALLEY...NEAR YUMA. THE GFS TEMP GUIDANCE SHOWED NO APPRECIABLE CHANGE FROM SUNDAY TO MONDAY AND THE MONDAY MAX TEMPS WERE ADJUSTED TO REFLECT THIS. ALSO...THE 850-700MB MEAN TEMP IS FORECAST TO BE AROUND 22 DEGREES C OVER LAS VEGAS MONDAY MORNING...SLIGHTLY WARMER THAN SUNDAY. THIS CORRELATES TO A 110 DEGREE HIGH IN LAS VEGAS BASED ON LOCAL STUDIES. SO...ANY EXCESSIVELY HOT CONDITIONS SUNDAY WILL LIKELY CONTINUE INTO MONDAY. WE WILL SEE A SIGNIFICANT PATTERN CHANGE TUESDAY AND WEDNESDAY AS A FAST MOVING SHORTWAVE TROUGH DROPS OUT OF THE PACIFIC NORTHWEST INTO THE NORTHERN INTERMOUNTAIN REGION. THERE IS SOME DISAGREEMENT ON TIMING AND DEPTH OF THIS FEATURE IN THE MEDIUM RANGE MODELS BUT THEY ALL INDICATE THE GENERAL PATTERN CHANGE WHICH WILL BRING A COOLING TREND AND GENERALLY DRY WEST TO NORTHWEST FLOW THROUGH THURSDAY. HIGH TEMPS SHOULD LOWER 3-5 DEGREES EACH DAY TUESDAY AND WEDNESDAY AND BOTTOM OUT NEAR NORMAL READINGS BY THURSDAY. && .AVIATION...FOR MCCARRAN...DIURNAL TYPE WINDS ARE EXPECTED THROUGH TODAY EXCEPT FOR WINDS ASSOCIATED WITH THUNDERSTORM OUTFLOW BOUNDARIES AND ANY THUNDERSTORMS THAT MAY FORM IN THE VALLEY THIS AFTERNOON. CLOUD CIGS THIS MORNING WILL GENERALLY BE AOA 15K FEET BUT COULD BECOME BKN AROUND 10K FEET AT TIMES THIS AFTERNOON. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...DIURNAL SURFACE WINDS ACROSS MOST AREAS TODAY EXCEPT NEAR THUNDERSTORMS AND OUTFLOW. ALSO, STRONGER WINDS WITH GUSTS TO NEAR 30KTS AGAIN IN THE OWENS VALLEY THIS AFTERNOON. THUNDERSTORM CHANCES ARE BEST OVER MOHAVE, EASTERN SAN BERNARDINO, CLARK AND LINCOLN COUNTIES TODAY. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ UPDATE...PADDOCK PREVIOUS DISCUSSION...SALMEN/ADAIR FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER  FXUS65 KVEF 142039 AFDVEF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 140 PM PDT FRI AUG 14 2015 .SYNOPSIS...LESS STORM COVERAGE AND WARMER TEMPERATURES ARE EXPECTED SATURDAY. HIGH PRESSURE WILL BECOME THE DOMINANT FEATURE SUNDAY AND MONDAY WITH VERY HOT CONDITIONS EXPECTED. A PACIFIC STORM SYSTEM IS THEN FORECAST TO BRING RELIEF FROM THE HEAT WITH TEMPERATURES CLOSER TO TYPICAL SEASONAL LEVELS AFTER MONDAY. && .DISCUSSION... THUNDERSTORM ACTIVITY HAS DEVELOPED ACROSS MOHAVE, FAR SOUTHERN CLARK, AND LINCOLN COUNTIES, WITH SHOWERS STARTING TO POP ACROSS EASTERN SAN BERNARDINO COUNTY. THESE WERE THE FAVORED AREAS FOR TODAY AND EXPECT THAT TO BE THE CASE THROUGH THE EARLY EVENING. COVERAGE IS MUCH LESS THAN THIS TIME YESTERDAY, WHICH IS ALSO EXPECTED. HOWEVER, WE WILL SEE HOW THINGS DEVELOP AND WHAT OUTFLOW BOUNDARIES DO WORKING WITH A VERY MOIST LOWER ATMOSPHERE. AS MENTIONED IN THE UPDATE THIS MORNING, THE STEERING FLOW IS FAVORABLE TO MOVE SOME OF THE SOUTHERN CLARK COUNTY CONVECTION TOWARD THE LAS VEGAS VALLEY. ALSO, THUNDERSTORMS THAT DEVELOP SHOULD HAVE HIGH PRECIP EFFICIENCY, WITH A WARM CLOUD DEPTH OF 14KFT, K INDEX IN THE 30S, PW OF OVER AN INCH, AND SUB-CLOUD LAYER RH OF 40-50 PERCENT. THUNDERSTORMS ARE EXPECTED TO WANE THIS EVENING. ADDITIONAL STORMS ARE POSSIBLE SATURDAY AFTERNOON WITH HIGH PRESSURE REMAINING EAST OF THE AREA, BUT BELIEVE COVERAGE WILL BE EVEN LESS THAN TODAY. BY SUNDAY, THE UPPER-LEVEL HIGH TRANSITIONS TO SOUTHWEST ARIZONA AND SOUTHERN CALIFORNIA, ENDING ANY CHANCE FOR STORMS. AS THE HIGH SHIFTS TO SOUTHWEST ARIZONA AND WE DRY OUT, TEMPERATURES WILL CLIMB. THE LATEST GUIDANCE CONTINUES TO INDICATE SUNDAY WILL BE THE HOTTEST DAY WITH HEAT LINGERING INTO MONDAY. BASED ON JUST TEMPERATURES, THE EXCESSIVE HEAT WARNING LOOKS GOOD. BUT ALSO, THE HOT TEMPERATURES COMBINED WITH DEWPOINTS IN THE 30S MAYBE 40S DURING THE AFTERNOON WOULD CREATE A HEAT WE WOULD CERTAINLY FEEL, WHICH WE HAVE NOT HAD FOR A WHILE. IF THAT IS NOT ENOUGH, SATURDAY WILL BE WARMING NICELY AND OVERNIGHT LOWS WILL REMAIN SOMEWHAT ELEVATED, WHICH WILL CREATE A MULTI-DAY COMBINED HOT STREAK THAT MAY TAKE A TOLL ON THE BODY BY SUNDAY AND MONDAY. SO, THE WILL KEEP THE EXCESSIVE HEAT WARNING AS IS. AFTER MONDAY, MODELS CONTINUE TO INDICATE A SIGNIFICANT PATTERN CHANGE, WITH A FAST MOVING SHORTWAVE TROUGH DROPPING FROM THE PACIFIC NORTHWEST INTO THE NORTHERN INTERMOUNTAIN REGION. MODELS SEEM TO BE IN A LITTLE BETTER AGREEMENT THAT THE TROUGH WILL BRING A COOLING TREND, WITH READINGS GETTING BACK TOWARD NORMAL BY THURSDAY. THE TROUGH WILL ALSO LIKELY INCREASE WINDS A BIT, BTU NOTHING SIGNIFICANT IS ANTICIPATED AT THIS TIME. && .AVIATION...FOR MCCARRAN...ISOLATED THUNDERSTORM ACTIVITY WILL BRING ERRATIC WINDS AT TIMES THROUGH 03Z SATURDAY. MAINLY FEW-SCT CLOUDS AOA 15KFT WITH PERIODS OF 10KFT CIGS ASSOCIATED WITH THUNDERSTORMS. OTHERWISE...NORMAL DIURNAL WIND TRENDS ARE EXPECTED. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...DIURNAL SURFACE WINDS ACROSS MOST AREAS TODAY EXCEPT IN AREAS IMPACTED BY THUNDERSTORM ACTIVITY. MAINLY EAST OF A KDAG TO KDRA TO KELY LINE. WINDS WITH GUSTS TO NEAR 30KTS ARE EXPECTED IN THE OWENS VALLEY THIS AFTERNOON. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ DISCUSSION...PADDOCK AVIATION.....BERC FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER  FXUS65 KVEF 181626 RRA AFDVEF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 926 AM PDT SAT JUL 18 2015 .SYNOPSIS...RICH MOISTURE ASSOCIATED WITH NOW DECAYING HURRICANE DOLORES WILL PUSH INTO THE REGION TODAY INCREASING THE POTENTIAL FOR HEAVY DOWNPOURS AND FLASH FLOODING. STORM CHANCES WILL BE GREATEST ACROSS SAN BERNARDINO...CLARK...AND MOHAVE COUNTIES TODAY. MOISTURE WILL PUSH FURTHER NORTH SUNDAY ENCOMPASSING THE ENTIRE AREA WITH CONTINUED FLASH FLOOD POTENTIAL. MOISTURE WILL GRADUALLY DECREASE NEXT WEEK TOWARDS MORE TYPICAL SUMMER VALUES BUT SLIGHT CHANCES FOR STORMS WILL REMAIN FOR MANY AREAS THROUGH MIDWEEK. && .MESOSCALE FORECAST UPDATE... NEXT IMPULSE IS MAKING ITS WAY ACROSS THE MORONGO AND YUCCA VALLEYS THIS MORNING. SHOWERS AND THUNDERSTORMS ARE ASSOCIATED WITH THIS WAVE, PUSHING NORTHEAST INTO SAN BERNARDINO COUNTY. AS THIS WAVE PUSHES NORTHEAST, IT WILL MOVE INTO A VERY MOIST ATMOSPHERE. WHILE THERE IS SOME CAPPING THIS MORNING ACROSS CLARK, MOHAVE, AND EASTERN SAN BERNARDINO COUNTIES, EXPECT THAT TO CHANGE AS DIURNAL HEATING CONTINUES. THE LAS VEGAS VALLEY HAD SURFACE DEWPOINTS AROUND 60 DEGREES THIS MORNING, BUT THAT IS MIXING OUT SOME WITH THE BREEZY SOUTH TO SOUTHWEST WINDS. AS THE WAVE APPROACHES THIS DESTABILIZING AREA AND THE PRESENCE OF LARGE-SCALE LIFT ASSOCIATED WITH AN UNUSUALLY STRONG UPPER LEVEL JET FOR JULY, EXPECT STORMS TO DEVELOP ACROSS SAN BERNARDINO, SOUTHERN CLARK AND MOHAVE COUNTIES THROUGH THE DAY. SPC MESO ANALYSIS OF MICROBURST POTENTIAL IS GRADUALLY EXPANDING ACROSS THE AFOREMENTIONED AREAS AND SHOULD CONTINUE AS DESTABILIZATION CONTINUES. ALSO WOULD NOT BE SURPRISED TO SEE SOME SMALL HAIL GIVEN THE CAPE IN THE 0 TO -20 C LAYER IN THE VEF 12Z SOUNDING. THE SOUNDING ALSO INDICATES A WARM CLOUD DEPTH OF JUST OVER 12K FEET, SUB-CLOUD LAYER RELATIVE HUMIDITY AROUND 40-50 PERCENT, PRECIPITABLE WATER VALUES JUST OVER ONE INCH, AND A K-INDEX IN THE UPPER 20S. ALL THESE PARAMETERS INDICATE THE POTENTIAL FOR WARM RAIN PROCESSES AND VERY PRECIPITATION EFFICIENT RAINFALL TODAY. HIGHER MOISTURE CONTENT RESIDES ACROSS EASTERN SAN BERNARDINO AND MOHAVE COUNTIES, MAKING THE POTENTIAL EVEN HIGHER. RAINFALL RATES OF 2 INCHES PER HOUR ARE NOT OUT OF THE QUESTION WITH THE STRONGER STORMS THAT DEVELOP. ONE ITEM WORKING IN OUR FAVOR IS INDIVIDUAL STORM MOTION WILL BE SOUTHWEST TO NORTHEAST AROUND 20 KNOTS. THE CONCERN THEN BECOMES REDEVELOPMENT, TRAINING, BACKBUILDING OF CONVECTION ACROSS THE SAME LOCATIONS. && .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT. ISSUED 255 AM PDT FRI JUL 17 2015 ITS BEEN AN ACTIVE NIGHT ACROSS OUR REGION WITH PERSISTENT AND OCCASIONALLY QUITE STRONG STORMS IN FAR SOUTHERN CLARK COUNTY AND NOW PRIMARILY IN MOHAVE COUNTY. STORMS EARLIER IN THE EVENING EXHIBITED IMPRESSIVE CORES AND PRODUCED PROLIFIC LIGHTNING AS THEY ENTERED INTO THE LAUGHLIN-BULLHEAD CITY AREA BEFORE MIGRATING EAST AND DROPPING SIGNIFICANT RAINFALL IN THE KINGMAN AND GOLDEN VALLEY AREAS. SUSPECT THE TREND FOR THE NEXT COUPLE HOURS WILL BE TOWARDS A SLOW WEAKENING WITH RESIDUAL SHOWERS AND ISOLATED THUNDER PUSHING INTO EASTERN MOHAVE COUNTY THROUGH THE MORNING HOURS. ADDITIONAL STORMS IN FAR NORTHERN MOHAVE COUNTY MAY PERSIST AS WELL BUT SLOWLY PUSH EASTWARD. THERE MAY BE A FEW WEAK AND ISOLATED SHOWERS THAT FORM ACROSS SOUTHEAST SAN BERNARDINO COUNTY EARLY IN THE MORNING AS WELL WHERE SOME CLOUDS ARE NOTED ON INFRARED IMAGERY BUT NOTHING OVERLY STRONG OR ORGANIZED IS EXPECTED UNTIL AFTER SUNRISE WHEN THINGS GET A LITTLE MORE INTERESTING. BY DAYBREAK JUDGING BY SATELLITE TRENDS MUCH OF THE REGION SHOULD START OFF DEVOID OF ANY SUBSTANTIAL CLOUD COVER. THE ONLY EXCEPTION MIGHT BE NORTHERN MOHAVE COUNTY WHICH COULD SEE SOME CLOUD DEBRIS LASTING INTO MID MORNING. WITH RICH MOISTURE IN PLACE...MOSTLY CLEAR SKIES TO START THE DAY...AND INCREASING JET SUPPORT TO ENHANCE LIFT...ALL SIGNS POINT TO POTENTIALLY EXPLOSIVE CONVECTIVE DEVELOPMENT DURING THE MID TO LATE MORNING HOURS. FORECAST SOUNDINGS ALSO SUPPORT THIS NOTION...WITH SIGNIFICANT CAPE VALUES FORECASTED PARTICULARLY IN CLARK...EASTERN SAN BERNARDINO...AND MOHAVE COUNTIES. PRIMARY CONCERN WILL BE VERY HEAVY DOWNPOURS AND FLASH FLOODING...BUT DEEP WESTERLY WIND PROFILE WILL ALSO SUPPORT SOME PULSE SEVERE STORMS AND POTENTIALLY ORGANIZED STORM STRUCTURES AT TIMES. WITH DEWPOINTS POOLING IN THE 65-70F+ RANGE ACROSS RIVERSIDE AND IMPERIAL COUNTIES IN FAR SOUTHERN CALIFORNIA...AND THIS MOISTURE PUSHING NORTHWARD THROUGH THE DAY...IVE EXPANDED THE FLASH FLOOD WATCH WESTWARD TO INCLUDE THE MORONGO BASIN AND WESTERN MOJAVE DESERT. LONG STORY SHORT...EXPECT POCKETS OF STRONG STORMS IN THE REGION TODAY AND FLASH FLOODING IS A SIGNIFICANT CONCERN. NOT ALL AREAS WILL RECEIVE RAIN...BUT I AM CONFIDENT SOME AREAS WILL SEE POTENTIALLY DANGEROUS THUNDERSTORMS CAPABLE OF PRODUCING LIFE THREATENING FLASH FLOODING. BEYOND THIS AFTERNOON...CONVECTIVE TRENDS WILL DEPEND ON HOW THINGS UNFOLD THROUGH THE COURSE OF THE DAY. MUGGY AND OVERCAST CONDITIONS ARE LIKELY ACROSS THE REGION WITH AREAS OF SHOWERS AND THUNDERSTORMS. MOISTURE WILL CONTINUE TO ADVANCE NORTH SATURDAY NIGHT INTO SUNDAY...AND WATCH EXTENSIONS & EXPANSIONS WILL NEED TO BE CONSIDERED IN SUBSEQUENT SHIFTS. .LONG TERM...MONDAY THROUGH FRIDAY. 255 AM PDT FRI JUL 17 2015 MOISTURE WILL REMAIN ABUNDANT MONDAY AND IT IS POSSIBLE THE REMAINS OF DOLORES AND ITS MID LEVEL CIRCULATION WILL DRIFT INTO SOUTHERN CALIFORNIA AND COULD RESULT IN ANOTHER DAY OF FLASH FLOOD CONCERNS. BY TUESDAY WE MAY BEGIN TO DRY OUT SOMEWHAT AS FLOW TURNS SOUTHWESTERLY BUT OFTEN TIMES MODELS SCOUR OUT OUR MOISTURE TOO QUICKLY...SO THIS IS SOMETHING THAT WILL NEED TO BE CONSIDERED. IN FACT...THE GFS MAINTAINS ELEVATED PRECIPITABLE WATER VALUES THROUGH WEDNESDAY AFTERNOON AND AM TEMPTED TO BELIEVE THIS GIVEN THE SEASONS TREND OF MOISTURE RELUCTANT TO SCOUR OUT OF THE REGION AFTER A MOISTURE PUSH. DIDNT MAKE SIGNIFICANT CHANGES TO THE EXTENDED RANGE AS MY FOCUS WAS MORE ON THE SHORT TERM BUT POPS IN THE EXTENDED MAY NEED TO BE RAISED THROUGH WEDNESDAY. AFTER WEDNESDAY MOSTLY DRY CONDITIONS SHOULD PREVAIL BUT DEPENDING ON WHERE THE MONSOON HIGH BUILDS BACK IN...THE BREAK MAY BE BRIEF WITH HINTS OF MORE PACIFIC TROPICAL ACTIVITY AND A POSSIBLE RETURN OF A SOUTHERLY FLOW BY NEXT WEEKEND. && .AVIATION...FOR MCCARRAN...SOUTHERLY WINDS EXPECTED IN THE MORNING HOURS WITH QUICKLY DETERIORATING CONDITIONS EXPECTED BY THE LATE MORNING AS SHOWERS AND THUNDERSTORMS DEVELOP IN THE AREA. SOUTH TO SOUTHWEST WINDS IN THE 15-20 KT RANGE WITH GUSTS TO 30KTS EXPECTED...HOWEVER AS USUAL THUNDERSTORMS WILL ADD A DEGREE OF VARIABILITY AND UNCERTAINTY TO THE FORECAST. WIND GUSTS NEAR STORMS MAY EXCEED 35KTS WITH CIGS BELOW 10K POSSIBLE AT TIMES AS WELL AS POCKETS OF CONVECTIVE TURBULENCE. OTHERWISE BKN-OVC CLOUD COVER EXPECTED THROUGH THE AFTERNOON ABOVE 12K. SHOWER AND THUNDERSTORM CHANCES WILL PERSIST OVERNIGHT. ALL APPROACH CORRIDORS WILL BE SUSCEPTIBLE TO THUNDERSTORM ACTIVITY TODAY. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...SHOWERS AND THUNDERSTORMS EXPECTED ACROSS THE REGION TODAY...ESPECIALLY FROM MID MORNING ONWARD. GREATEST CHANCES WILL BE ALONG AND SOUTH OF A KDAG-KLAS-KSGU LINE BUT ISOLATED STORMS WILL BE POSSIBLE ELSEWHERE. BKN-OVC CONDITIONS ABOVE 10K POSSIBLE DURING THE AFTERNOON WITH AREAS OF GUSTY AND ERRATIC SURFACE WINDS NEAR STORMS AS WELL AS POCKETS OF CONVECTIVE TURBULENCE. SHOWERS AND THUNDERSTORMS MAY PERSIST OVERNIGHT AS WELL. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE NEEDED TODAY IN MOHAVE...SAN BERNARDINO...AND CLARK COUNTIES. OTHERWISE...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ MESOSCALE FORECAST UPDATE...PADDOCK DISCUSSION...OUTLER FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER  FXUS65 KVEF 181626 RRA AFDVEF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 926 AM PDT SAT JUL 18 2015 .SYNOPSIS...RICH MOISTURE ASSOCIATED WITH NOW DECAYING HURRICANE DOLORES WILL PUSH INTO THE REGION TODAY INCREASING THE POTENTIAL FOR HEAVY DOWNPOURS AND FLASH FLOODING. STORM CHANCES WILL BE GREATEST ACROSS SAN BERNARDINO...CLARK...AND MOHAVE COUNTIES TODAY. MOISTURE WILL PUSH FURTHER NORTH SUNDAY ENCOMPASSING THE ENTIRE AREA WITH CONTINUED FLASH FLOOD POTENTIAL. MOISTURE WILL GRADUALLY DECREASE NEXT WEEK TOWARDS MORE TYPICAL SUMMER VALUES BUT SLIGHT CHANCES FOR STORMS WILL REMAIN FOR MANY AREAS THROUGH MIDWEEK. && .MESOSCALE FORECAST UPDATE... NEXT IMPULSE IS MAKING ITS WAY ACROSS THE MORONGO AND YUCCA VALLEYS THIS MORNING. SHOWERS AND THUNDERSTORMS ARE ASSOCIATED WITH THIS WAVE, PUSHING NORTHEAST INTO SAN BERNARDINO COUNTY. AS THIS WAVE PUSHES NORTHEAST, IT WILL MOVE INTO A VERY MOIST ATMOSPHERE. WHILE THERE IS SOME CAPPING THIS MORNING ACROSS CLARK, MOHAVE, AND EASTERN SAN BERNARDINO COUNTIES, EXPECT THAT TO CHANGE AS DIURNAL HEATING CONTINUES. THE LAS VEGAS VALLEY HAD SURFACE DEWPOINTS AROUND 60 DEGREES THIS MORNING, BUT THAT IS MIXING OUT SOME WITH THE BREEZY SOUTH TO SOUTHWEST WINDS. AS THE WAVE APPROACHES THIS DESTABILIZING AREA AND THE PRESENCE OF LARGE-SCALE LIFT ASSOCIATED WITH AN UNUSUALLY STRONG UPPER LEVEL JET FOR JULY, EXPECT STORMS TO DEVELOP ACROSS SAN BERNARDINO, SOUTHERN CLARK AND MOHAVE COUNTIES THROUGH THE DAY. SPC MESO ANALYSIS OF MICROBURST POTENTIAL IS GRADUALLY EXPANDING ACROSS THE AFOREMENTIONED AREAS AND SHOULD CONTINUE AS DESTABILIZATION CONTINUES. ALSO WOULD NOT BE SURPRISED TO SEE SOME SMALL HAIL GIVEN THE CAPE IN THE 0 TO -20 C LAYER IN THE VEF 12Z SOUNDING. THE SOUNDING ALSO INDICATES A WARM CLOUD DEPTH OF JUST OVER 12K FEET, SUB-CLOUD LAYER RELATIVE HUMIDITY AROUND 40-50 PERCENT, PRECIPITABLE WATER VALUES JUST OVER ONE INCH, AND A K-INDEX IN THE UPPER 20S. ALL THESE PARAMETERS INDICATE THE POTENTIAL FOR WARM RAIN PROCESSES AND VERY PRECIPITATION EFFICIENT RAINFALL TODAY. HIGHER MOISTURE CONTENT RESIDES ACROSS EASTERN SAN BERNARDINO AND MOHAVE COUNTIES, MAKING THE POTENTIAL EVEN HIGHER. RAINFALL RATES OF 2 INCHES PER HOUR ARE NOT OUT OF THE QUESTION WITH THE STRONGER STORMS THAT DEVELOP. ONE ITEM WORKING IN OUR FAVOR IS INDIVIDUAL STORM MOTION WILL BE SOUTHWEST TO NORTHEAST AROUND 20 KNOTS. THE CONCERN THEN BECOMES REDEVELOPMENT, TRAINING, BACKBUILDING OF CONVECTION ACROSS THE SAME LOCATIONS. && .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT. ISSUED 255 AM PDT FRI JUL 17 2015 ITS BEEN AN ACTIVE NIGHT ACROSS OUR REGION WITH PERSISTENT AND OCCASIONALLY QUITE STRONG STORMS IN FAR SOUTHERN CLARK COUNTY AND NOW PRIMARILY IN MOHAVE COUNTY. STORMS EARLIER IN THE EVENING EXHIBITED IMPRESSIVE CORES AND PRODUCED PROLIFIC LIGHTNING AS THEY ENTERED INTO THE LAUGHLIN-BULLHEAD CITY AREA BEFORE MIGRATING EAST AND DROPPING SIGNIFICANT RAINFALL IN THE KINGMAN AND GOLDEN VALLEY AREAS. SUSPECT THE TREND FOR THE NEXT COUPLE HOURS WILL BE TOWARDS A SLOW WEAKENING WITH RESIDUAL SHOWERS AND ISOLATED THUNDER PUSHING INTO EASTERN MOHAVE COUNTY THROUGH THE MORNING HOURS. ADDITIONAL STORMS IN FAR NORTHERN MOHAVE COUNTY MAY PERSIST AS WELL BUT SLOWLY PUSH EASTWARD. THERE MAY BE A FEW WEAK AND ISOLATED SHOWERS THAT FORM ACROSS SOUTHEAST SAN BERNARDINO COUNTY EARLY IN THE MORNING AS WELL WHERE SOME CLOUDS ARE NOTED ON INFRARED IMAGERY BUT NOTHING OVERLY STRONG OR ORGANIZED IS EXPECTED UNTIL AFTER SUNRISE WHEN THINGS GET A LITTLE MORE INTERESTING. BY DAYBREAK JUDGING BY SATELLITE TRENDS MUCH OF THE REGION SHOULD START OFF DEVOID OF ANY SUBSTANTIAL CLOUD COVER. THE ONLY EXCEPTION MIGHT BE NORTHERN MOHAVE COUNTY WHICH COULD SEE SOME CLOUD DEBRIS LASTING INTO MID MORNING. WITH RICH MOISTURE IN PLACE...MOSTLY CLEAR SKIES TO START THE DAY...AND INCREASING JET SUPPORT TO ENHANCE LIFT...ALL SIGNS POINT TO POTENTIALLY EXPLOSIVE CONVECTIVE DEVELOPMENT DURING THE MID TO LATE MORNING HOURS. FORECAST SOUNDINGS ALSO SUPPORT THIS NOTION...WITH SIGNIFICANT CAPE VALUES FORECASTED PARTICULARLY IN CLARK...EASTERN SAN BERNARDINO...AND MOHAVE COUNTIES. PRIMARY CONCERN WILL BE VERY HEAVY DOWNPOURS AND FLASH FLOODING...BUT DEEP WESTERLY WIND PROFILE WILL ALSO SUPPORT SOME PULSE SEVERE STORMS AND POTENTIALLY ORGANIZED STORM STRUCTURES AT TIMES. WITH DEWPOINTS POOLING IN THE 65-70F+ RANGE ACROSS RIVERSIDE AND IMPERIAL COUNTIES IN FAR SOUTHERN CALIFORNIA...AND THIS MOISTURE PUSHING NORTHWARD THROUGH THE DAY...IVE EXPANDED THE FLASH FLOOD WATCH WESTWARD TO INCLUDE THE MORONGO BASIN AND WESTERN MOJAVE DESERT. LONG STORY SHORT...EXPECT POCKETS OF STRONG STORMS IN THE REGION TODAY AND FLASH FLOODING IS A SIGNIFICANT CONCERN. NOT ALL AREAS WILL RECEIVE RAIN...BUT I AM CONFIDENT SOME AREAS WILL SEE POTENTIALLY DANGEROUS THUNDERSTORMS CAPABLE OF PRODUCING LIFE THREATENING FLASH FLOODING. BEYOND THIS AFTERNOON...CONVECTIVE TRENDS WILL DEPEND ON HOW THINGS UNFOLD THROUGH THE COURSE OF THE DAY. MUGGY AND OVERCAST CONDITIONS ARE LIKELY ACROSS THE REGION WITH AREAS OF SHOWERS AND THUNDERSTORMS. MOISTURE WILL CONTINUE TO ADVANCE NORTH SATURDAY NIGHT INTO SUNDAY...AND WATCH EXTENSIONS & EXPANSIONS WILL NEED TO BE CONSIDERED IN SUBSEQUENT SHIFTS. .LONG TERM...MONDAY THROUGH FRIDAY. 255 AM PDT FRI JUL 17 2015 MOISTURE WILL REMAIN ABUNDANT MONDAY AND IT IS POSSIBLE THE REMAINS OF DOLORES AND ITS MID LEVEL CIRCULATION WILL DRIFT INTO SOUTHERN CALIFORNIA AND COULD RESULT IN ANOTHER DAY OF FLASH FLOOD CONCERNS. BY TUESDAY WE MAY BEGIN TO DRY OUT SOMEWHAT AS FLOW TURNS SOUTHWESTERLY BUT OFTEN TIMES MODELS SCOUR OUT OUR MOISTURE TOO QUICKLY...SO THIS IS SOMETHING THAT WILL NEED TO BE CONSIDERED. IN FACT...THE GFS MAINTAINS ELEVATED PRECIPITABLE WATER VALUES THROUGH WEDNESDAY AFTERNOON AND AM TEMPTED TO BELIEVE THIS GIVEN THE SEASONS TREND OF MOISTURE RELUCTANT TO SCOUR OUT OF THE REGION AFTER A MOISTURE PUSH. DIDNT MAKE SIGNIFICANT CHANGES TO THE EXTENDED RANGE AS MY FOCUS WAS MORE ON THE SHORT TERM BUT POPS IN THE EXTENDED MAY NEED TO BE RAISED THROUGH WEDNESDAY. AFTER WEDNESDAY MOSTLY DRY CONDITIONS SHOULD PREVAIL BUT DEPENDING ON WHERE THE MONSOON HIGH BUILDS BACK IN...THE BREAK MAY BE BRIEF WITH HINTS OF MORE PACIFIC TROPICAL ACTIVITY AND A POSSIBLE RETURN OF A SOUTHERLY FLOW BY NEXT WEEKEND. && .AVIATION...FOR MCCARRAN...SOUTHERLY WINDS EXPECTED IN THE MORNING HOURS WITH QUICKLY DETERIORATING CONDITIONS EXPECTED BY THE LATE MORNING AS SHOWERS AND THUNDERSTORMS DEVELOP IN THE AREA. SOUTH TO SOUTHWEST WINDS IN THE 15-20 KT RANGE WITH GUSTS TO 30KTS EXPECTED...HOWEVER AS USUAL THUNDERSTORMS WILL ADD A DEGREE OF VARIABILITY AND UNCERTAINTY TO THE FORECAST. WIND GUSTS NEAR STORMS MAY EXCEED 35KTS WITH CIGS BELOW 10K POSSIBLE AT TIMES AS WELL AS POCKETS OF CONVECTIVE TURBULENCE. OTHERWISE BKN-OVC CLOUD COVER EXPECTED THROUGH THE AFTERNOON ABOVE 12K. SHOWER AND THUNDERSTORM CHANCES WILL PERSIST OVERNIGHT. ALL APPROACH CORRIDORS WILL BE SUSCEPTIBLE TO THUNDERSTORM ACTIVITY TODAY. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...SHOWERS AND THUNDERSTORMS EXPECTED ACROSS THE REGION TODAY...ESPECIALLY FROM MID MORNING ONWARD. GREATEST CHANCES WILL BE ALONG AND SOUTH OF A KDAG-KLAS-KSGU LINE BUT ISOLATED STORMS WILL BE POSSIBLE ELSEWHERE. BKN-OVC CONDITIONS ABOVE 10K POSSIBLE DURING THE AFTERNOON WITH AREAS OF GUSTY AND ERRATIC SURFACE WINDS NEAR STORMS AS WELL AS POCKETS OF CONVECTIVE TURBULENCE. SHOWERS AND THUNDERSTORMS MAY PERSIST OVERNIGHT AS WELL. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE NEEDED TODAY IN MOHAVE...SAN BERNARDINO...AND CLARK COUNTIES. OTHERWISE...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && $$ MESOSCALE FORECAST UPDATE...PADDOCK DISCUSSION...OUTLER FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER  FXUS65 KVEF 042137 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 237 PM PDT Wed Apr 4 2018 .SYNOPSIS...Warm and dry weather will remain through tonight and Thursday. Expect unsettled weather conditions this weekend as a low pressures moves inland. Primary concerns over the weekend will be strong winds on Saturday; however, shower chances will increase across the area as well, especially along the Sierra. Dry and calm conditions will return early next week before strong winds return Tuesday. Expect periods of high clouds and well above normal Temperatures through the weekend and into next week. && .SHORT TERM...Through Friday. Rather low impact weather through the end of the work week. Zonal flow aloft will remain through Friday, with a few weak shortwaves translating through it. These small disturbances - ejected from the base of an upstream upper low - will lead to enhanced periods of high to mid clouds through Friday. Increased sky coverage and cloud thickness will create a bit of challenge when it comes to forecasting diurnal temperature ranges. While the area will experience increasing heights aloft and increasing temperatures through the rest of the week, the cloud cover may limit the full potential of the afternoon temperatures. Forecast temperatures will increase 6-10 degrees above normal to cap off the work week. Unsettled weather will begin to creep back into the forecast Friday in the way of breezy to locally strong winds ahead of the next synoptic disturbance. Western portions of the Mojave Desert will likely experience the strongest winds on Friday between 20-30 MPH and gusts approaching 40 MPH. This may require feature wind headlines and will need to be monitored over the next couple of forecast cycles. Elsewhere, breezy south-southwest wind regime will develop. In addition to the increased winds ahead of this weekend's system, there will be an increased chance for showers for Friday, mainly over the east Sierra and the northern zones. With snow levels around 10,000 feet, most of the precip will fall as rain. .LONG TERM...Saturday through Wednesday. An incoming shortwave is expected to bring widespread gusty winds to much of the region Saturday afternoon along with significant precipitation to the southern Sierra Saturday as an AR pushes mainly into the Pacific Northwest. There will still be enough influence from the deeper moisture to impact the southern Sierra with significant rainfall which will occur over mainly the western slopes, but we could see enough spillover to bring good rain to the eastern slopes and possibly the northern Owens Valley. Snow levels will remain quite high on Saturday, but could drop to around 7500 feet toward the end of the event. At this time, precipitation impacts look to be rather minimal. This shortwave will quickly move through the area and precipitation east of the Owens Valley looks to be rather minimal as much of the precipitation will be blocked by the Sierra and the lack of any significant forcing. However, Lincoln County may see an increase in showers Saturday evening as forcing does increase along a cold front that will move through the area. Much drier air will push into behind the front with dry conditions expected Sunday and Monday. Gusty southwest winds ahead of a cold front will impact much of the area Saturday afternoon with the strongest winds across San Bernardino, Clark, southern Lincoln, and Mohave Counties. Strong thermal and surface pressure gradients combined with upper support should allow for fairly widespread advisory level winds during the afternoon. Enhanced downslope winds off the Spring Mountains may also lead to higher gusts over the western portions of the Vegas Valley. Although there will be some gusty northwest winds behind the front, it does not look to be widespread and the highest winds will likely remain over Esmeralda and central Nye Counties. Another fast moving trough will then swing across Tuesday with southwest winds stirring up again and possibly becoming quite strong in the lee of the southern Sierra and across south central Nevada. The trough is forecast to move over the Rockies by Wednesday morning leaving weak ridging and fair weather Wednesday ahead of another trough lining up to move inland. Even though each trough will bring a slight temperature dip, readings will remain above normal with highs in the 70s and 80s for all zones except the mountains. && .AVIATION...For McCarran...Light winds following diurnal trends anticipated through Thursday morning. Increased speeds likely develop Thursday afternoon, with speed between 10-12 kts. VFR conditions with mid to high clouds. CIGs between 15-20 kft with skies fluctuating between SCT and BKN. For the rest of southern Nevada, northwest Arizona and southeast California...Light winds following diurnal trends through Thursday morning. Southerly wind regime will develop across the region Thursday afternoon; Wind speeds will generally fall between 5-15 knots, except at sites across the western Mojave Desert (KDAG) where speeds will range from 15-25 knots. Generally, CIGs between 15-20 kft with skies fluctuating between SCT and BKN are expected. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM/AVIATION...Boothe LONG TERM.............Gorelow For more forecast information...see us on our webpage: http://weather.gov/lasvegas or follow us on Facebook and Twitter